Gliederung

Background: Neoadjuvant chemotherapy (pCHT) is an established method to reduce tumor size (downstaging) in breast cancer patients before performing breast conserving therapy. The consequences of pCHT on tumor cell dissemination in these patients are not known. The study was designed to evaluate (1) the tumor dissemination after pCHT, (2) the relevance of apoptotic disseminated tumor cells after pCHT and (3) the prognostic significance of disseminated tumor cells after pCHT.

Methods: Patients with advanced breast cancer (pT3 / pT4) who received primary chemotherapy at the Dept. of Gyn/OB, University of Tuebingen, Germany, were eligible for this study. Bone marrow aspiration was performed at the time of surgery.

Results: Disseminated tumor cells were detected in 154 of 301 breast cancer patients (51%) after completed pCHT. Tumor dissemination was observed more frequently in patients with no change / progressive disease (NC+PD: 72%) than in those who showed partial or complete remission of the primary tumor (PR+CR: 49%). Apoptotic disseminated tumor cells were detected in 20% of breast cancer patients. In the situation of progressive disease (n=5) no apoptotic cells were observed. Patients who experienced partial or complete remission of their primary tumor were more likely to have apoptotic tumor cells in bone marrow compared to those with stable disease or progression. Presence of disseminated tumor cells after primary chemotherapy turned out to be an independent prognostic factor for relapse free survival (p=0.022; RR=2.63) and overall survival (p=0.032, RR=2.23).

Discussion: According to our results the primary chemotherapy is not able to eliminate all disseminated tumor cells. It is yet not determined if pCHT has an influence on the metastatic potential of disseminated tumor cells. Nonetheless, patients who responded to pCHT showed more circulating apoptotic cells than patients with stable or progressive disease. The presence of tumor cells in bone marrow after preoperative chemotherapy remains an independent prognostic factor.